/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using Spring.Util;

namespace Spring.Aop.Support;

/// <summary>
/// ITypeFilter that looks for a specific attribute being present on a class
/// </summary>
/// <author>Juergen Hoeller</author>
/// <author>Mark Pollack  (.NET)</author>
public class AttributeTypeFilter : ITypeFilter
{
    private readonly Type attributeType;
    private readonly bool checkInherited;

    /// <summary>
    /// The attribute <see cref="Type"/> for this filter.
    /// </summary>
    public Type AttributeType
    {
        get { return attributeType; }
    }

    /// <summary>
    /// Indicates, whether this filter considers base types for filtering.
    /// </summary>
    public bool CheckInherited
    {
        get { return checkInherited; }
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="AttributeTypeFilter"/> class for the
    /// given attribute type.
    /// </summary>
    /// <param name="attributeType">Type of the attribute to look for.</param>
    public AttributeTypeFilter(Type attributeType) : this(attributeType, false)
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="AttributeTypeFilter"/> class for the
    /// given attribute type.
    /// </summary>
    /// <param name="attributeType">Type of the attribute.</param>
    /// <param name="checkInherited">if set to <c>true</c> [check inherited].</param>
    public AttributeTypeFilter(Type attributeType, bool checkInherited)
    {
        AssertUtils.ArgumentNotNull(attributeType, "attributeType");
        if (!typeof(Attribute).IsAssignableFrom(attributeType))
        {
            throw new ArgumentException(
                string.Format(
                    "The [{0}] Type must be derived from the [System.Attribute] class.",
                    attributeType));
        }

        this.attributeType = attributeType;
        this.checkInherited = checkInherited;
    }

    /// <summary>
    /// Should the pointcut apply to the supplied <see cref="System.Type"/>?
    /// </summary>
    /// <param name="type">The candidate <see cref="System.Type"/>.</param>
    /// <returns>
    /// 	<see langword="true"/> if the advice should apply to the supplied
    /// <paramref name="type"/>
    /// </returns>
    public bool Matches(Type type)
    {
        if (checkInherited)
        {
            return AttributeUtils.FindAttribute(type, attributeType) != null;
        }
        else
        {
            object[] atts = type.GetCustomAttributes(attributeType, false);
            return ArrayUtils.HasLength(atts);
        }
    }
}
